1. Field of the Invention
The present invention relates to signal generators and in particular to startable signal generators of high accuracy.
2. Description of the Prior Art
Precise interval measurements are essential in nuclear and ballistic time-of-flight tests, radar ranging and in the characterization of active components, such as integrated circuits. In making such interval measurements, utilization of a pulse train of short duration pulses with accurately controlled interpulse spacing is desirable for use with digital signal processing equipment.
The basic principles of generating microwave signals are well known. It has been proposed to use series and parallel pulse forming networks for the generation of microwave signals. Particular forms of network configurations of both series and parallel forms are described in an article by Jerald F. Ross in the Microwave Journal, September 1967, pages 98-105. In the proposal by Ross, a series network comprising T-connections of transmission lines utilizing coaxial lines and T-networks of open circuited and short circuited stubs are used to generate the microwave signals. However, in such series networks and other similar arrangements known in the art, the size of the systems tend to be unnecessarily larger than desired because of reflections due to mismatching of the transmission lines and the pulse forming networks. In addition, the Ross technique results in very large insertion loss. There is a need in the field of pulse generators of high frequency to provide significantly compact structures that are reliable and accurate with low insertion loss.